How do we map a spotted star? Many stars are polka dotted, but we generally can’t observe their spots directly. Astronomers developed and tested a new tool using data from NASA missions that can help map the spot patterns on a star’s surface using data we’ve collected on the hunt for exoplanets, worlds beyond our solar system. When a planet passes in front of, or transits, its host star, it blocks a tiny bit of the light. Transits have revealed thousands of planets outside our solar system, and